With the development of science and technology, the smart mobile phones have been popularized and bring convenience to the people's daily life.
In accordance with one technique, when an object is captured by a smart mobile phone, two pictures of the object which are captured at different capturing angels by two cameras in a manner of stereoscopic vision and a corresponding depth image is generated, so that the actual distance from the object to the smart mobile phone is determined.
In the method for measuring a distance mentioned above, if a distance from an object far away should be measured, the distance between the two cameras needs to be increased (by taking an actual distance from the object to the smart mobile phones beyond 1000 meters as an example, the distance between the two cameras is at least a counts of meters). However, since in the procedure of designing a smart mobile phone, it is mainly focused on the portability of the mobile phone and the size is strictly limited, it leads to that the method for manufacturing the distance of as mentioned above cannot measure the distance of the object in a long distance.